Plug valve



Nov. 22, 1938. E. c. MCFARLANEl 2,137,248

PLUG vALvE Filed Dec. 5, 19.55 1 2 sheets-sheet 1 4a f( nu ATTORNEY.

Nov. 22, 1938. E. c. MCFARLANE 2,137,248

PLUG VALVE f n Filed Dec. 5, 1956 2 sheets-sheet 2 INVENTOR.

u Edwin C.M?Fcr|ome BY @ZM A TTORNEY.

55 curately show whether the plu'g is fully seated Patented Nov. 22, 193s 2,137,243 PATENT OFFICE PLUG VALVE Edwin C. McFarlane, Pearl River, N. Y. Application December s, 1936, semi No. 114,344

1 3 Claims.

(Granted under the act of Much 3, isz-i3, as.

` amended April 30,

'I'his invention relates to valves and is directed more particularly to that type of valvewherein the sealing member of the valve is in the form of a frustoconical plug adapted to cooperate with f a correspondingly tapered seat in the valve casing. Valves of this kind, sometimes referred to as plug cocks, are used extensively in the arts and are particularly emcient in that they automatically take upl wear and serve to maintain a tight nt through long periods. 'I'hey are, however, open to the objection that the plug of the valve tends to stick or freeze to its seat when left inactive for protracted periods, so as to render the operation of the valve extremely diillcult.

\This objection is widely prevalent in valves of this kindparticularly in view of the fact that,

when the valve is employed to control high iiuid pressures, the plug must have a tight engagement with its seat, which tends to produce the sticking to which I have referred.

In view of the tendency of these valves to stick,

'it has been the common vpractice to make the taper of the plug relatively abrupt, for the finer the taper the greater tendency there is to stick. On the other hand, the finer the taper, the better the valve is able to withstand high gaseous pressures. I'he fact remains that a valve of this kind having a small taper cannot be satisfactorily operated, so that a greater gtaper which tends to promote leakage is the common practice.

One object of the present invention is to provide a simple and eflicient valve of the character described, so, constituted that it may be made with a very fine taper to enable it to properly hold high pressures and, yet maybe easily operated when desired. i In practically carrying out the present invention, I accomplish this result and others by-associating with the valve, means* adapted to effect the positive seating 'or' yunseating of the plug when desired, so that the plug lmay be slightly unseated. to permit of its rotation and .subsequentiy forced rmly to its seatwhen in proper adjusted position. All this is accomplished in accordance with the presentI invention through the manipulation of asingle handle or operating f y member adapted to be bodily shifted into diiler'-I ent positions at the will of the operator to render it capable of eitherseating or lunseating the plug or rotating the'plug as may be desired. v

The practical `diiliculty with such an. arrangement, 'in a general sense, is that the plug isu housed within a casingwhere its position cannot be observed and consequently the presentiinvention embodies also indicating devices which acor not andalso the position of the 'port through the valve plu`g, so that the operator, by reference to these indicating devices, cannot inadvertently desired.v In this respect the valve of the present invention is absolutely safe and there can be no doubt at any time as -to the position of the plug thereof. Y

Anotherobject of the invention is to so constitute the valve that vthe packing thereof may be changed without shutting down Ithe line in which the valve is incorporated, as will hereinafter be more fully described, for the present invention makes renewal of packings a simple matter which may be carried out in a safe and emcient way without disturbing the position of the plug in its casing.

Features oi the invention, other than those adverted to, will be apparent from the hereinafter detailed description and claims, when read in conjunction with the accompanying drawings.

'I'he accompanying drawings illustrate differ.- ent practical embodiments of the invention, but the constructions therein shown are to be understood as illustrative, only, and not as definingA Figure 2 is an endyiew of the valve shown in Figure 1 with one lateral half of the valve also shown in central section.

Figure 3 is a plan view of the Figures 1 and 2.

Figure 4 is a iragmental perspective view l showing details of indicating devices incorporated in the construction.

Figure 5 is a ira'gmental central section of a modified form of construction. 'I'he present invention may be incorporat either in straight-through valves or two, three or four wayA cocks and in valves-embodying one or more tiers of ports, but, for the purpose of illus'- tration, I have chosen to show a simple straightthrough valve. As shown the valve embodies a casing i having alined passages 2 terminating in e flanges 3 to incorporate the valve in a line. The lvalve has a removable seat 4 which may conveniently be of bronze, stainlesssteel 'or the like, although this ,seat may be omitted if desired. The plug lisshaped'to' properly cooperate with theseat and both the plug and the seat are in practice preferably made with a relatively fine .taper as the, valve of the present invention will properly allow of this design. The plug passage 6 is adapted to aline with .the passagesA 2 of the casing to allow ofthe passage of duid through the valve orsaid plug may be turnedthrough 90 `degrees to shut `oi! the now. The top of the casing is closed by a bonnet 1 and the valve stem l passes centrally through the bonnet and has a packing gland l with associated packing l0. With the gland cooperates a valve shown in gland yoke I I adapted to adjust thegland through manipulation of gland nuts I2, associated with studs I3 tapped into the bonnet.

Threaded into the top of the casing I are a pair of standards I4, rigid with the housing and are locked in place by lock nuts I5. The standards extend upwardly in parallel relation through holes in the bonnet and are threaded with an oversized thread to receive clamping nuts I5 which serve to secure the bonnet to the casing. A gasket I1 is interposed between the bonnet and the housing and bears on the upper edge of the removable seat 4 to hold the seat in position and form a tight joint between the housing and the bonnet. The standards I4 extend well above the bonnet and carry a yoke I8, the upper end of the standards being reduced and threaded to pass through the yoke with shims I9 to'permit of adjustment and nuts bind the yoke to the standards.

The yoke is provided with a central opening, threaded as indicated at 2 I, to cooperate with the threaded outer periphery of a differential ring 22, the inner periphery of which is also threaded at 23 to cooperate with a stator nut 24 which has radially extending arms 25, bifurcated to straddle the standards I4.

The valve stem extends upwardly from the plug 5, throughl the gland and packing and through the stator nut 24, but it is reduced in diameter below the stator nut to form a shoulder 26 on which rests a"plate 21, locked against rotation to the valve stem and provided with an upstanding pointer 28 adapted to cooperate with legends Closed and Open on the opposite faces of the stator nut. The plate 21 is so positioned with reference to the valve stem that the pointer 28 indicates the position of the passage 6 of the plug, so that when the pointer is juxtaposed with Open, the plug will be in the open straight through position of Figure 1 whereas,

when the pointer is juxtaposed with Closed",

the plug will be in a 90 relation to this position, i. e., in port-closing position. Thus the operator can see at a glance at the pointer whether ,or

not the valve is open or closed` and there can .be no question about it.

The valve stem 8 is further reduced at the upper face of the stator mit to provide a shoulder 29 and on this shoulder rests a'flanged sleeve 38 onthe upper end of which and on a shoulder formed by a further reduction in the diameter of stem 8 is seated a male coupling 3I locked to thevalve stem against rotation by a nut 32. The connection between the coupling 3| and the valve stem is preferably a squared connection, so that there is a positive lock against relative rotation between these parts. A grease cup 33 is shown associated with the top of the valve stem and thevalve stem is provided interiorly with appropriate ducts (not shown) to feed the lubricant therefrom to the operating parts of the valve.

By this construction the stator nut is secured against movement longitudinally of l the valve stem and must move with the stem in this direction, butthe valve stem is free to rotate' withY respect to the stator nut.

The differential ring 22 is, aspreviously stated, threaded on both its inner and outer peripheries, but the threads of these peripheries are of different pitch. I do not restrict myself to particular pitches but I find it convenient to make the external thread a four pitch and the internal thread a 4% pitch, so that, when the dierential ring is rotated, the diierential action which results Aunseated.

will bring about longitudinal movement of the stator nut in accordance with a 40 pitch thread, so as to give a relatively slow movement with the application of great power.

Rotary movement is adapted to be imparted to the differential ring by a handle 34 having radially extending arms, the ends -of which carry knobs 35 whereby the handle may be readily manipulated. The handle has a central opening having a sliding t on the sleeve 30 between its flange and the male coupling 3|, so that the handle is freely rotatable on the sleeve 30 as well as longitudinally movable thereon without tilting. The handle is provided with an annular series lof holes 36 spaced on the same radius from the axis of the valve stem and both the differential ring and the male coupling 3l v are provided with pins or dogs 31 and 38, respectively, adapted selectively to be engaged with'the openings 36, to render either of these parts responsive to the operations of the handle.

Thus, if it is assumed that the plug is seated firmly on the seat 4, the handle is rst brought into the position shown in Figure 1 to bring the holes 36 in position to receive the pins 31. In this position, the handle will be locked to the differential ring, and if the handle is now rotated, in a counterclockwise direction, it will rotate the differential ring in a like direction and will, through a 40 pitch, elevate the stator nut, carrying with it the valve plug 5,u so that said plug is Definite indication of the internal operations is provided for by an indicator hand 39, the details of which are shown in Figure 4. This hand is pivoted to loosely revolve on a pin 40 which passes through a boss 4I at one end of the yoke I8 and`is held in place `thereon by a nut 42 as shown. A spring 43 encircles the pin 40 and its ends are offset to enter perforations 44 and 45 in the yoke and pointer respectively, so as to bias the pointer to rotate in a counterclockwise direction. The pointer may be duplicated at opposite faces of the yoke, so that an indication may be had from either snide of the valve. Mounted on one of the forked arms of the stator nut 24 is an adjusting screw 46, so positioned as to act upon the pointer 39 oif center and this 5ad` justing screw may be locked in adjusted position by a set screw 41.

The parts are so adjusted that when the plug 5 is seated the pointer 39 will pointto the word Tight on the yoke and as the stator nut is elevatedincident to the lifting or unseating of the plug, the adjusting screw 46 will push' up the pointer, so that by the time the plug is fullyl unseated, the pointer -will point to the word Loose on the yoke as will be clearly apparent from Figure l. Thus, as the operator` manipulates the handle,- he can watch the pointer and see exactly what is going on and can accurately determine when the plug is unseated.

After the plug has been unseated or brought into fLoose position, the handlel 34 is bodily rectilinearly moved in an upward direction on the valve stem, so as'to disengage holes 36 from 2,137,248 the plug will be indicated by the pointer 28,`as.

hereinbefore described, and by the pointers I8 of Figure 3 which point in the same direction as the passage 6. The direction of rotation for the loosening and tightening movements is indicated by the arrows 49 shown in Figure 3.

After the plug has been adjusted to the desired position, the handle is moved from interlocked relation with the coupling 3| into interlockedrelation with respect to the differential ring and is thereupon manipulated to again lower the plug into seated relation with respect Ato the valve, the accomplishment of which will'.be indicated by the pointer 39 which will thereupon point to the word 'Iight. It will thus be apparent that the condition of the plug will be at all times manlfest to the operator through observation of the appropriate pointers and there will never be any question in his mind as to the exact condition of the parts.

, Inasmuch as the longitudinal shifting of the plug on to andoil of its seat is accomplished under considerable power, the taper of the plug may be made relatively i'lne to hold high pressures and yet permit of the operation of the parts withoutappreclable manual. exertion.

It will also be apparent that the structure described obviates the necessity of shutting down the line in which the valve is incorporated to repack the gland for the gland and its operating parts are entirely independent of the operating parts of the plug. Thus the plug maybe held tightly to its seat, while the nuts I2 of the gland yoke Il are loosened to permit o f re-packing, or the stem may be even re-packed while the plug is in elevated position and free from its seat, for the annular channel 50 'at the top of the plug will be engaged by a complementary annular protuberance on the interior of the bonnet to form a relatively close seal at this point, independently of the gland and packing.

In the construction of Figures 1-4,. the plug is moved to and from its seat through a differential ring. In Figure 5, however, this differential ring is omitted and a nut 5|, freely rotatable on the valve stern, is threaded for direct cooperation with the threads of the yoke la. The structure is otherwise the same as in the preceding figures, except that the increased pitch is not present in the construction of Figure 5.

An important advantage of the present invention over prior constructionsl is the vmarked simplicity of the arrangement described. The

parts are so constructed that there is practically nothing to get out of order and the construction is thoroughly reliable under all conditions. This operation is so simple that it does not require any particular degree of skill for its manipulation and the indicating means are such as to effectually safeguard the valve against undue ,y strain which is not infrequently placed on valves by operators as a precautionary measure in order that the operator may be sure that the valve is.

left in the condition desired.l In this connection.

ber 39 operates, while the legends Closed and Open on the stator nut also constitute a dial with which the pointer 28 cooperates. Inpractice these'legends may be other than those specied or graduations, such as are frequently foundon the dials, may be used. in lieu thereof.-

The present invention does not Agreatly change Y the conventional valve casing construction. The

operating parts are exteriorly of the casing and y rotatable outside of the bonnet and constitute, in effect,

-adjuncts to a valve of substantially conventional construction. All these operating devices are in full view and may be readily inspected without dismantling any part. The operations are carried out through the employment of a single handle movable alternately along a rectilinear path into either of two positions which are definite and predetermined, so that it is actually impossible for the uninitiated to operate the valve improperly.

'I'he foregoing detailed description sets forth the invention in its preferred practical forms, but

the invention is to be understood as fully commensurate with the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. l

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

1. A plug valve comprising a casing, a plug mounted for axial and rotary movement within the casing and having an operating stem, rotary means operatively connected` with the stem for imparting axial movement thereto to unseat and reseat the plug, an operatingy device mountedon the stem for imparting rotary movement to the plug, and an operating handle slidably and rotatably mounted on the plug stem between said rotary means and said operating device and adapted forf engagement with either said rotary means or said operating device to impart successive axial and rotary movements tothe stem and plug.

2. A plug valve comprising a casing, a plug mounted for axial and rotary movement within the casing and having an operating stern proljecting through the casing, an internally screw- 3. A plug valve comprising a casing, a plug,

mounted for axial and rotary movement within the casing and having an operating stem projecting through the casing, an internally screwthreaded yoke mounted on the casing through which the stem projects, an externally screwthreaded cllar within the yoke and sleeved on the stem for imparting axial movement thereto, means for holding said collar against rotation, a

ingjits threads inoperative engagement with the threads of the yoke and collar, a clutch member fixed on the stem for imparting rotary movement thereto.- an operating handle slidably and rotatably mounted on the stem between said ring and clutch member for engaging either said ring or clutch member, and means on the handle for operatively engaging said ring or clutch* member for imparting successive axial and rotary movements to the stem and plug.

EDWIN C. MCFARIANE.

internallyand externally screw- 'threaded ring between .saidyoke and collar havthe legends Loose and Tight on the yoke f constitute a dial over which the indicating mem-,- 

